In vain we shall penetrate more and more deeply the secrets of the structure of the human body, we shall not dupe nature; we shall die as usual.

A philosopher will not believe what he sees because he is too busy speculating about what he does not see.

A work of morality, politics, criticism will be more elegant, other things being equal, if it is shaped by the hand of geometry.

Our sun enlightens the planets that belong to him; why may not every fixed star also have planets to which they give light?

We must always skim over pleasures. They are like marshy lands that we must travel nimbly, hardly daring to put down our feet.

Since the princes take the Earth for their own, it's fair that the philosophers reserve the sky for themselves and rule there, but they should never permit the entry of others.

If I held all the thoughts of the world in my hand, I would be careful not to open it.